Intriguing diversity of Bacillus anthracis in eastern Poland--the molecular echoes of the past outbreaks.

The multiple locus VNTRs analysis (MLVA) revealed the presence of five genotypes in a group of 10 Bacillus anthracis isolates from epidemiologically unrelated cases of bovine-anthrax in eastern Poland. Eight tested isolates possessed the pagA and capB genes indicating the presence of both virulence plasmids, while two isolates revealed only pagA and lacked pXO2. The MLVA and DNA sequence analysis indicated that seven tested isolates represent four novel genotypes. Five tested strains revealed a unique 144 bp vrrB2 variant as well as 220 bp variant of vrrB1, implying the relatedness to the lineage B2. Consequently, we propose establishing of novel B2 strains sub-lineage. Multiple anthrax outbreaks, which took place in Poland several decades ago were proposed as a cause of intriguing diversity of B. anthracis observed in this study.